linux-kernel - Re: [PATCH v1 1/1] irqdomain: Refactor error path in __irq_domain_alloc

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Date:   Fri, 04 Aug 2023 18:33:07 +0100
From:   Marc Zyngier <maz@...nel.org>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Johan Hovold <johan+linaro@...nel.org>,
        linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v1 1/1] irqdomain: Refactor error path in
 __irq_domain_alloc_fwnode()

On 2023-08-04 17:49, Andy Shevchenko wrote:
> First of all, there is no need to call kasprintf() if the previous
> allocation failed. Second, there is no need to call for kfree()
> when we know that its parameter is NULL. Refactor the code accordingly.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  kernel/irq/irqdomain.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 0bdef4fe925b..d2bbba46c808 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -81,6 +81,8 @@ struct fwnode_handle
> *__irq_domain_alloc_fwnode(unsigned int type, int id,
>  	char *n;
> 
>  	fwid = kzalloc(sizeof(*fwid), GFP_KERNEL);
> +	if (!fwid)
> +		return NULL;
> 
>  	switch (type) {
>  	case IRQCHIP_FWNODE_NAMED:
> @@ -93,10 +95,8 @@ struct fwnode_handle
> *__irq_domain_alloc_fwnode(unsigned int type, int id,
>  		n = kasprintf(GFP_KERNEL, "irqchip@%pa", pa);
>  		break;
>  	}
> -
> -	if (!fwid || !n) {
> +	if (!n) {
>  		kfree(fwid);
> -		kfree(n);
>  		return NULL;
>  	}

What are you trying to fix?

We have a common error handling path, which makes it easy to
track the memory management. I don't think this sort of bike
shedding adds much to the maintainability of this code.

Now if you have spotted an actual bug, I'm all ears.

       M.
-- 
Jazz is not dead. It just smells funny...